In existing gas turbines, dampers (or Helmholtz dampers) are normally provided to reduce pulsations and vibrations within the gas turbine combustion chamber. These dampers provide a damper volume attached to the combustion chamber by a damper neck. However, this arrangement has the drawback that the neck and the mechanical connections holding the damper in place need to be designed to tolerate thermal expansions and thermal loads. This requires extra complexity and expense in damper design and manufacture. We have therefore appreciated that it would be desirable to provide an improved damper design.